OEM Carrier 40VA Control Transformer HT01BD236 for Model C48A502752

This OEM step-down transformer is the factory-specified replacement for the Carrier C48A502752 packaged unit. The transformer converts 120V line voltage down to 24V AC to power the entire low-voltage control circuit — including the thermostat, contactor coil, and control board. When the transformer fails, the system goes completely silent: the thermostat loses power, no relay clicks, and no staging occurs. A blown transformer is often the result of a short in the low-voltage wiring or a failed component drawing excess current, so always inspect the secondary circuit before installing a replacement.

• Specs: 40VA rating | 120V primary / 24V secondary | OEM part number HT01BD236 | Factory-matched output voltage tolerance for stable control circuit operation
• OEM vs Generic: OEM transformers are wound and insulated to Carrier's exact VA and thermal specs. Generic units may sag under load, causing erratic thermostat behavior, nuisance lockouts, or premature contactor coil failure — costing far more than the price difference.
• Install difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or terminal connectors. Verify incoming voltage and secondary output after installation before restoring full power. Always check for secondary-side shorts before powering up.
• Warranty: 1-year OEM factory warranty. Orders placed before cutoff ship same business day from our climate-controlled warehouse.

Compatibility: Designed for the Carrier C48A502752 packaged unit. Verify your unit's control circuit voltage requirements against your data plate before ordering. If you're unsure of fitment, our HVAC parts specialists will confirm compatibility before your order ships — just reach out via chat or phone.